Conventional covered binders for releasably securing and protecting sheets of paper or the like therein are well known. Such binders are provided in a variety of sizes and typically have a covering formed from two sheets or plies in overlying relationship. The covering is bent or folded along parallel lines to form a spine portion with two cover portions flexibly secured to opposite edges of the spine portion. Reinforcement sheets, usually comprised of flat sheets of cardboard or the like, are provided in the cover portions between the plies. A cardboard backplate is typically inserted between the plies in the spine portion to add strength, rigidity and form to the binder.
To promote the retention of paper therein, most binders include some form of paper retaining apparatus or binder mechanism. One popular binder mechanism comprises an elongated ring support plate having a series of snap-rings supported along the length thereof at selected positions. Such snap-rings pass through holes provided along one edge of the paper or sheet material adapted to be retained within the binder. Such a binder mechanism can be purchased in a variety of sizes and is typically secured along the spine portion of the binder.
To facilitate attachment of the binder mechanism to the binder, the ring support plate defines a series of holes spaced between the rings. Relatively inexpensive binders utilize rivet-like fasteners which are driven through the spine portion and through the holes in the ring support plate to secure the binder mechanism to the binder. During assembly, the free end of each rivet is peened into contact with the ring support plate thereby securing the paper retaining binder mechanism to the binder.
Albeit economical from a manufacturer's viewpoint to use a rivet to assemble the paper retaining binder mechanism to the binder, such an assembly process leaves at least a head portion of the rivet exposed to an outer surface of the binder cover. The exposure of the rivet presents a number of drawbacks including an unaesthetic and unattractive appearance for the binder and thereby reducing its customer appeal.
Manufacturers have been known, therefore, to provide an outer covering which extends along the spine portion to hide the head portions of the rivets. As will be appreciated, the addition of an outer covering material adds both material and manufacturing costs to the binder. Moreover, adding a cover to hide the rivet heads detracts from automation of the binder manufacturing process and is labor intensive.
Because customers appear willing to spend more for binders without exposed rivet head portions, other types of binders with paper retaining mechanisms have been proposed. One proposal involves a one-piece molded binder covering having a spine with cover panels integrally molded with and hingedly connected to the spine portion of the binder covering. A plurality of tubular posts on which the paper retaining or binder mechanism is mounted are molded integrally with the spine portion of the binder. A series of drive or clinch rivets are pressed into the tubular post to secure the binder mechanism to the binder.
As mentioned above, binders are usually provided in a variety of sizes including 1 inch, 1.50 inch, 2 inch, and 3 inch sizes. Of course, different size binders necessarily have different size binder mechanisms including appropriately sized snap-rings. As will be appreciated, the spine portion on the binder is sized to accommodate and is proportional to the particular snap-ring size of the binder. Accordingly, each one-piece molded binder covering which is different in size requires a separate mold or die set to produce that particular size binder. The use of different die sets in fabricating or molding different size binder encumbers automation of the binder manufacturing process and adds substantial cost to each binder.
Another proposed solution involves the insertion of an elongated hollow rectangular plastic backplate in the spine portion of the binder between the plastic plies. The ring hardware is secured to the backplate by metal rivets the free end of which depend through the ring hardware. The backplate is provided with preformed holes which accommodate the rivets. Ultimately, the metal rivets are sonically welded to the backplate. As will be appreciated, aligning the rivets with the preformed holes in a backplate hidden beneath a cover is labor intensive and adds to the cost of the binder.
Benefits provided by these proposals are offset by their additional cost, manufacturing problems, and added size inherent with such designs. Thus, there remains a need and desire for an economical method and apparatus for fastening a paper retaining mechanism to a binder while maintaining a fastener concealed from an outer surface of the binder.